Track roller assembly having a replaceable flange

ABSTRACT

A track roller assembly supports and guides the link rails of the endless track of a track-type vehicle as the endless track travels along the ground. Contact between the link rails and the roller assembly is at the tread portion of the roller. A replaceable tread ring on the roller tread portion has a non-metallic outer tread portion which contacts the link rails. The tread ring is held in place by a replaceable flange plate. A separate seal plate holds the various seals in place when the flange plate is removed for replacement of the tread ring or the flange plate. Conventional track roller assemblies have non-replaceable flange plates and metal tread portions which produce considerable wear on the mating link rails. The subject roller assembly prolongs the useful life of the link rails and provides an easily replaceable flange plate and tread ring.

TECHNICAL FIELD

This invention relates generally to a track roller assembly forsupporting and guiding the endless track of a track type vehicle, andmore particularly to a track roller assembly having a replaceable flangeplate for retaining a tread ring in place on the roller assembly.

BACKGROUND ART

Self-laying track-type vehicles utilize an endless track chain assemblyjoined together by interconnected link assemblies. The link assembliesinclude overlapping link members which form a pair of continuous rails.A plurality of roller assemblies bear the vehicle's weight, and guidethe track chain by engaging the link rails as the chain assembly rotatesabout a drive sprocket wheel and one or more idler wheels. The rollerassemblies rotate from frictional engagement with the link rails.Considerable noise and vibration is generated from the metal to metalcontact of the roller treads with the link rails. The noise andvibrations are sometimes magnified by other components of the vehicle.Additionally, the continuous contact between the rails and the rollertreads produces wear of the two components with resulting replacement orrepair. Such replacement or repair increases the operating cost anddowntime of the vehicle.

One type of track roller having a replaceable rim and an elastic ringbelow the rim is disclosed in U.S. Pat. No. 3,580,093, issued on May 25,1971, to K. Tomizawa. The replaceable rim is a metal ring and theelastic ring is made of rubber or synthetic resin. An end plate havingan outer flange is secured to the roller hub and holds the rim andelastic ring in place. This arrangement requires the outer flangedplates to hold the rim and elastic ring in place.

Another type of track roller having a resilient mounted tread isdisclosed in U.S. Pat. No. 3,910,128, issued on Oct. 7, 1975, to R. L.Boggs et al. The tread portion of this roller includes an innerresilient collar and an outer metallic ring. The tread portions are heldbetween a pair of flanges and the flanges are secured in place bythreaded retaining means. This particular arrangement would appear tofunction satisfactorily for its intended purpose. However, this assemblycontains a considerable number of parts and requires time and effort toassemble the parts together.

The present invention is directed to overcoming one or more of theproblems as set forth above.

DISCLOSURE OF THE INVENTION

In one aspect of the invention, a track roller assembly for guiding andsupporting an endless track of a self-laying track-type vehicle includesa shaft mounted to the vehicle, a hub member mounted on the shaft, and aseal plate secured to the hub member. The roller assembly furtherincludes a replaceable tread ring mounted on the hub member, and areplaceable flange plate engaging the tread ring and secured to the hubmember.

In another aspect of the invention, a replaceable composite tread ringfor a roller assembly includes a non-metallic tread portion, and ametallic base portion having a Unshape in cross-section. The baseportion is bonded to the tread portion and encloses portions of thenon-metallic tread portion.

Continuous frictional rolling contact between the metal link rails andthe metal roller treads of prior art endless track assemblies produceswear of the link rails and roller treads. This wear results in repair orreplacement of the links or rollers, or both. The continuous contactbetween the moving link rails and the rollers also generatesconsiderable noise.

The subject roller assembly with replaceable flange and replaceablecomposite tread ring, with non-metallic tread portion, reduces the wearon the links and rollers and makes replacement of the roller treadsquick and simple. The flange plate is also quickly and easilyreplaceable. The subject invention also reduces the noise generated bycontact between the rollers and link rails. By reducing wear, the usefullife of the undercarriage parts is increased and operating andmaintenance costs are reduced, thereby providing increased value to thevehicle owner.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective view of a portion of the subjecttrack roller assembly with portions in section;

FIG. 2 is a diagrammatic plan view of a composite tread ring of thepresent invention;

FIG. 3 is a diagrammatic sectional view taken generally along the lines3--3 of FIG. 2;

FIG. 4 is a diagrammatic perspective view, partly in section, of secondembodiment of a composite tread ring of the present invention;

FIG. 5 is a diagrammatic perspective view, partly in section, of a thirdembodiment of a composite tread ring of the present invention;

FIG. 6 is a diagrammatic perspective view, partly in section of a fourthembodiment of a composite tread ring of the present invention; and

FIG. 7 is a diagrammatic sectional view of the track roller assembly ofthe present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the drawings, a track roller assembly 10 for guidingand supporting the link rails 12 of an endless track of a self-layingtrack-type vehicle includes a shaft 14, a hub member 16, seal plates 18,and replaceable flange or retainer plates 20. The shaft 14 has first andsecond end portions 22,24 which are adapted to secure the rollerassembly 10 to the vehicle. The hub member 16 has first and secondflange portions 26,28 and first and second support portions 30,32, andis rotatably mounted on the shaft 14 by first and second sleeve bearings34,36. A replaceable tread ring 38 is mounted on each of the first andsecond support portions 30,32. Preferably, the tread ring 38 is acomposite ring and includes an inner metallic base portion 40 and anouter non-metallic tread portion 42, with the inner base portion 40 andouter tread portion 42 being bonded together.

Each replaceable flange plate 20 includes a flanged area 44 and amounting area 46 with the flange area 44 being adapted to engage thetread ring 38 and the mounting area 46 adapted to engage andsubstantially encircle the seal plate 18. A plurality of first threadedfasteners 48 are adapted to releasably secure the seal plates 18 to thehub member 16, and a plurality of second threaded fasteners 50 areadapted to releasably secure the flange plates 20 to the hub member 16.The seal plate 18 includes a plurality of through holes 52 toaccommodate the second fasteners 50. The roller assembly 10 includes aplurality of metal to metal seal assemblies 56 positioned between theshaft 14 and the seal plate 18, and a resilient seal 54 between the sealplate 18 and the hub member 16. The seal plates 18 maintains the seals54 and seal assemblies 56 in place when the flange plates 20 areremoved.

The tread rings 38 are adapted to slide onto the support portions 30,32and therefore include an inner diameter dimension D which is slightlygreater than the outer diameter dimension d of the support portions30,32. In order to prevent rotation of the tread rings 38, the baseportion 40 of each tread ring 38 has a side surface 58 and preferablyincludes one or more projections 60 extending outwardly of the sidesurface. Each of the flange plates 20 has one or more slots or cavities62 and each cavity 62 is adapted to receive one of the projections 60 tothereby prevent rotation of the tread rings 38. Preferably, each treadring 38 includes at least two projections 60 which are positioned about1800 from each other. Each projection 60 defines an opening 64therethrough, which will accommodate fingers of a tool to help removethe tread ring 38 if it should become locked or frozen onto the supportportions 30,32.

With particular reference to FIG. 4, a second embodiment of a compositetread ring 66 includes a metal inner base portion 68 and a non-metallicouter tread portion 70. The base portion 68 is U-shaped in cross-sectionand includes first and second side legs 72,74. The side legs 72,74 areadapted to enclose portions of the non-metallic tread portion 70, andthe base portion 68 and tread portion 70 are bonded together. Althoughnot illustrated, the base portion could include outwardly extendingprojections, similar to the projections 60 on the tread ring 38.

With particular reference to FIG. 5, a third embodiment of a compositetread ring 66' is illustrated. Tread ring 66' is similar to the treadring 66 and includes a metal inner base portion 68' and a non-metallicouter tread portion 70'. As in the previous embodiment, the base portion68' is Unshaped in cross-section and includes first and second side legs72',74' which enclose portions of the non-metallic tread portion 70'.The non-metallic tread portion 70' includes an outer segment 76 having atread surface 78, and an inner segment 80 positioned between the outersegment 76 and the base portion 68'. In order to enhance the heatconducting properties of the inner segment 80, a plurality of metallicparticles 82 are dispersed therein. To further enhance the heatconducting properties, the inner segment 80 can include a plurality ofcolumns 83 extending through the outer segment 76 and terminating at thetread surface 78. The number and orientation of the columns 83 can bevaried to obtain optimum heat transfer between the inner segment 80 andthe tread surface 78.

With particular reference to FIG. 6, a fourth embodiment of a compositetread ring 66" is illustrated. As in the previous embodiments, the treadring 6611 includes a metal inner base portion 84 and a non-metallicouter tread portion 86. Tread ring 66" includes a non-metallic middleportion 88 positioned between the outer tread portion 86 and the innerbase portion 84. The middle portion 88 has a U-shape in cross-sectionand includes first and second legs 90,92 which enclose portions of theouter tread portion 86. The legs 90,92 extend to the tread surface 94 ofthe tread portion 86. The middle portion 88 is bonded to the baseportion 84 and to the tread portion 86, and has a plurality of metallicparticles 82' dispersed therein. If desirable, a plurality of columns,such as columns 83 in the previous embodiment, can extend from themiddle portion 88 to the tread surface 94. The inner base portion 84 hasa plurality of projections 60', with each projection having an opening64'. Preferably, the non-metallic portions of each embodiment arecomprised of urethane, although other non-metallics could be used.

INDUSTRIAL APPLICABILITY

With reference to the drawings, the subject track roller assembly 10 andreplaceable composite tread ring 38 are particularly useful for reducingwear of the link rails 12 and for increasing the life of theundercarriage components. The subject invention also provides for easyreplacement of the replaceable flange plates 20 and the composite treadrings 38.

After extended periods of operation of the track roller assembly 10, thetread portion 42 of the tread ring 38 may become worn and requirereplacement. Also, the flange plate 20 may become worn and need to bereplaced or repaired. To accomplish replacement of the flange plate 20or the tread ring 38, the threaded fasteners 50 are removed, whichallows the flange plate 20 to be removed. The tread ring 38 can be thenbe removed since it is held in place by the flange plate 20. If thetread ring should be frozen onto the support portions 30,32 a pullingtool can be inserted into the openings 64 of the projections 60 and thetread ring 38 will be forcibly pulled from the support portions 30,32.Since the seal plate 18 remains secured in place by the threadedfasteners 48, the resilient seals 54 and the metal to metal seals 56remain undisturbed and lubricant within the roller assembly 10 is notlost.

A new tread ring 38 is now positioned onto the support portions 30,32and a new or repaired flange plate 20 is secured in place by thethreaded fasteners 50. The roller assembly is now ready to be placedback in service.

Other aspects, objects and advantages of this invention can be obtainedfrom a study of the drawings, the disclosure, and the appended claims.

We claim:
 1. A track roller assembly for guiding and supporting anendless track of a self-laying track-type vehicle, comprising:a shaftadapted to be secured to the vehicle; a hub member having a flangeportion and a support portion, said hub member being rotatably mountedon said shaft; a seal plate; a plurality of first fasteners adapted toreleasably secure said seal plate to said hub member; a replaceabletread ring mounted on said support portion of said hub member; areplaceable flange plate adapted to engage said tread ring and to engageand encircle said seal plate; and a plurality of second fastenersadapted to releasably secure said flange plate to said hub member.
 2. Atrack roller assembly, as set forth in claim 1, wherein said tread ringhas a first inner diameter D, and said support portion has a secondouter diameter d, said first diameter D being greater than said seconddiameter d.
 3. A track roller assembly, as set forth in claim 1, whereinsaid tread ring has a side surface and a projection extending outwardlyof said side surface.
 4. A track roller assembly, as set forth in claim3, wherein said flange plate has a cavity adapted to receive saidprojection.
 5. A track roller assembly, as set forth in claim 1, whereinsaid tread ring has a said surface and a plurality of projectionsextending outwardly of said side surface.
 6. A track roller assembly, asset forth in claim 5, wherein at least two of said projections arepositioned about 180° from each other.
 7. A track roller assembly, asset forth in claim 5, wherein said flange plate has a plurality ofcavities, each of said cavities being adapted to receive one of saidprojections.
 8. A track roller assembly, as set forth in claim 6,wherein said flange plate has a plurality of cavities, two of saidcavities being adapted to receive said two projections which arepositioned about 180° from each other.
 9. A track roller assembly, asset forth in claim 1, wherein said second fasteners extend through saidflange plate and said seal plate.
 10. A track roller assembly, as setforth in claim 6, wherein each of said two projections defines anopening therethrough.
 11. A track roller assembly, as set forth in claim1, including a plurality of seals positioned between said shaft and saidhub member, said seal plate being adapted to maintain said seals inplace when said flange plate is removed.
 12. A track roller assembly, asset forth in claim 1, wherein said replaceable tread ring has an innermetallic base portion and an outer non-metallic tread portion, said baseand tread portions being bonded together.
 13. A track roller assembly,as set forth in claim 12, wherein said metal base portion is U-shaped incross-section and includes side legs which are adapted to encloseportions of said non-metallic tread portion.
 14. A track rollerassembly, as set forth in claim 12, wherein said non-metallic treadportion includes an outer region having a tread surface and an innerregion positioned between said outer region and said base portion, saidinner region having a plurality of metallic particles dispersed therein.15. A track roller assembly, as set forth in claim 14, wherein saidinner region includes a plurality of columns extended through said outerregion and to said tread surface.